Field
Embodiments of the present invention relate to a vibration isolating structure for a power unit including an internal combustion engine equipped integrally with a transmission.
Description of the Related Art
A power unit has a plurality of power transmission mechanisms interposed in the process of transmitting rotational power of a crankshaft of an internal combustion engine to an output shaft through a clutch device and a transmission.
In general, a clutch device includes, on a primary driven gear, a torque damper for damping torque variations attendant on a shift of the clutch.
In addition, as described in Japanese Patent Laid-Open No. 2003-193854 (Patent Document 1), there is an example in which a plurality of torque dampers for damping the torque variations attendant on a shift of a transmission are disposed in order to suppress, as securely as possible, vibrations of the power unit.
Patent Document 1 discloses a configuration wherein a cam-type damper is disposed between a clutch output shaft and the input side of a gear transmission of a constantly meshed type, and a torque damper is disposed between a counter shaft (the output of the transmission) and an output shaft of the power unit.
In a power unit having a transmission, torque variations are generated with a timing of a change of the current shift position at the time of a gear shift, or due to reaction forces of driving generated between the vehicle and the road surface. To damp such large torque variations, in Patent Document 1, torque dampers are disposed both on the input side of the transmission and on the output side of the transmission, in an attempt to suppress the vibrations of the power unit as securely as possible.